Columns to drop from the design matrix. Cannot be used to
drop terms involving categoricals.

*args

Additional positional argument that are passed to the model.

**kwargs

These are passed to the model with one exception. The
eval_env keyword is passed to patsy. It can be either a
patsy:patsy.EvalEnvironment object or an integer
indicating the depth of the namespace to use. For example, the
default eval_env=0 uses the calling namespace. If you wish
to use a “clean” environment set eval_env=-1.

Returns

model

The model instance.

Notes

data must define __getitem__ with the keys in the formula terms
args and kwargs are passed on to the model instantiation. E.g.,
a numpy structured or rec array, a dictionary, or a pandas DataFrame.